This is a note to let you know that I've just added the patch titled
tracing: Fix possible NULL pointer dereferences
to the 3.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
tracing-fix-possible-null-pointer-dereferences.patch
and it can be found in the queue-3.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From lizefan@xxxxxxxxxx Mon Jun 10 14:15:28 2013
From: Namhyung Kim <namhyung.kim@xxxxxxx>
Date: Fri, 7 Jun 2013 17:01:16 +0800
Subject: tracing: Fix possible NULL pointer dereferences
To: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>, Steven Rostedt <rostedt@xxxxxxxxxxx>, Frederic Weisbecker <fweisbec@xxxxxxxxx>, Ingo Molnar <mingo@xxxxxxxxxx>, LKML <linux-kernel@xxxxxxxxxxxxxxx>, stable <stable@xxxxxxxxxxxxxxx>
Message-ID: <51B1A15C.5040108@xxxxxxxxxx>
From: Namhyung Kim <namhyung.kim@xxxxxxx>
commit 6a76f8c0ab19f215af2a3442870eeb5f0e81998d upstream.
Currently set_ftrace_pid and set_graph_function files use seq_lseek
for their fops. However seq_open() is called only for FMODE_READ in
the fops->open() so that if an user tries to seek one of those file
when she open it for writing, it sees NULL seq_file and then panic.
It can be easily reproduced with following command:
$ cd /sys/kernel/debug/tracing
$ echo 1234 | sudo tee -a set_ftrace_pid
In this example, GNU coreutils' tee opens the file with fopen(, "a")
and then the fopen() internally calls lseek().
Link:
http://lkml.kernel.org/r/1365663302-2170-1-git-send-email-namhyung@xxxxxxxxxx
Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Namhyung Kim <namhyung.kim@xxxxxxx>
Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx>
[ lizf: adjust context ]
Signed-off-by: Li Zefan <lizefan@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
include/linux/ftrace.h | 2 +-
kernel/trace/ftrace.c | 10 +++++-----
kernel/trace/trace_stack.c | 2 +-
3 files changed, 7 insertions(+), 7 deletions(-)
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -299,7 +299,7 @@ ssize_t ftrace_filter_write(struct file
size_t cnt, loff_t *ppos);
ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf,
size_t cnt, loff_t *ppos);
-loff_t ftrace_regex_lseek(struct file *file, loff_t offset, int origin);
+loff_t ftrace_filter_lseek(struct file *file, loff_t offset, int origin);
int ftrace_regex_release(struct inode *inode, struct file *file);
void __init
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -2626,7 +2626,7 @@ ftrace_notrace_open(struct inode *inode,
}
loff_t
-ftrace_regex_lseek(struct file *file, loff_t offset, int origin)
+ftrace_filter_lseek(struct file *file, loff_t offset, int origin)
{
loff_t ret;
@@ -3445,7 +3445,7 @@ static const struct file_operations ftra
.open = ftrace_filter_open,
.read = seq_read,
.write = ftrace_filter_write,
- .llseek = ftrace_regex_lseek,
+ .llseek = ftrace_filter_lseek,
.release = ftrace_regex_release,
};
@@ -3453,7 +3453,7 @@ static const struct file_operations ftra
.open = ftrace_notrace_open,
.read = seq_read,
.write = ftrace_notrace_write,
- .llseek = ftrace_regex_lseek,
+ .llseek = ftrace_filter_lseek,
.release = ftrace_regex_release,
};
@@ -3659,8 +3659,8 @@ static const struct file_operations ftra
.open = ftrace_graph_open,
.read = seq_read,
.write = ftrace_graph_write,
+ .llseek = ftrace_filter_lseek,
.release = ftrace_graph_release,
- .llseek = seq_lseek,
};
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
@@ -4261,7 +4261,7 @@ static const struct file_operations ftra
.open = ftrace_pid_open,
.write = ftrace_pid_write,
.read = seq_read,
- .llseek = seq_lseek,
+ .llseek = ftrace_filter_lseek,
.release = ftrace_pid_release,
};
--- a/kernel/trace/trace_stack.c
+++ b/kernel/trace/trace_stack.c
@@ -384,7 +384,7 @@ static const struct file_operations stac
.open = stack_trace_filter_open,
.read = seq_read,
.write = ftrace_filter_write,
- .llseek = ftrace_regex_lseek,
+ .llseek = ftrace_filter_lseek,
.release = ftrace_regex_release,
};
Patches currently in stable-queue which might be from namhyung.kim@xxxxxxx are
queue-3.4/tracing-fix-possible-null-pointer-dereferences.patch
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